Just bought a used Harman P68

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cpetku

Member
Dec 24, 2019
42
Clarkston MI
Other than basic cleaning (as found on the web) is there anything else I should do such as oiling motors/bearings?

I was told the unit has two seasons on her and is SN HF3037XX. Paid $2000 assuming it was like new. It came with basic 3PVP pipe and fittings but only half a thimble. Tested in my garage and all seems to work like it should so I have a new thimble with OAK on order. Hopefully the CV doesn't shut down delivery services.

One other question, when using the Duravent 3PVP-XXX (with silicon seals) do most self installers use black furnace cement? The duravent instructions implies this is optional.
 
I use black silicone tape (lowes/HD) for sealing vent joints. Oil the motors with 3 in1 oil for electric motors or anderol 465.
 
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The tape Ssyko is talking about works well, you'll have to cut it off (not hard at all) since it works by stretching & sealing to itself, but it sure is easier to get apart if you ever need to down the road.
I'm not sure what cleaning from the web you are talking about, but be sure to check the fines box & clean out the igniter area under the burn pot. You should get many years of trouble free service so long as it gets a thorough cleaning every year (both the stove and the flue piping).
You'll want to get a good surge protector for it, and maybe a True Sine Wave UPS or battery back up system depending on how long you'll need to run if you lose power. I have generator back-up & only need long enough to change over so I use a TSW UPS.
Enjoy it!
 
Thank you,

I wasn't sure if oil would combine with wood dust to cause more issues than it solved. The tape sounds a lot cleaner than the sealant as well.
 
Other than basic cleaning (as found on the web) is there anything else I should do such as oiling motors/bearings?

I was told the unit has two seasons on her and is SN HF3037XX. Paid $2000 assuming it was like new. It came with basic 3PVP pipe and fittings but only half a thimble. Tested in my garage and all seems to work like it should so I have a new thimble with OAK on order. Hopefully the CV doesn't shut down delivery services.

One other question, when using the Duravent 3PVP-XXX (with silicon seals) do most self installers use black furnace cement? The duravent instructions implies this is optional.


While you've got easy access, I'd take a good look at the distribution blower's wheel to see it's accumulated much dust, pet hair, etc. The whole unit is easy to pull. There are just two bolts that secure it plus two spade connected electrical wires and and a bolted ground wire. A single hex screw secures the blower wheel to the motor shaft. Depending on the environment the stove was previously used in, the blower wheel may be anywhere from pristine to horrifyingly packed with gunk. I'd also pull the ESP and give the whole exhaust pathway a rigorous cleaning. This will give you experience removing the ESP to check and clean it and allow a much safer deep clean of the internal exhaust.

You got a good deal price wise and the stove and will really enjoy it for year or perhaps decades to come.

Hugh
 
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Might as well check the fines box on it too...pretty sure its in the same location as my P61

 
While you've got easy access, I'd take a good look at the distribution blower's wheel to see it's accumulated much dust, pet hair, etc. The whole unit is easy to pull. There are just two bolts that secure it plus two spade connected electrical wires and and a bolted ground wire. A single hex screw secures the blower wheel to the motor shaft. Depending on the environment the stove was previously used in, the blower wheel may be anywhere from pristine to horrifyingly packed with gunk. I'd also pull the ESP and give the whole exhaust pathway a rigorous cleaning. This will give you experience removing the ESP to check and clean it and allow a much safer deep clean of the internal exhaust.

You got a good deal price wise and the stove and will really enjoy it for year or perhaps decades to come.

Hugh

Thanks, I have it all apart right now and will be cleaning everything.

I bought the Harman thinking I could remove the hopper then remove a plywood subfloor panel and use an electric winch to pull it straight up to the second floor. Wrong! Even after field stripping it of all motors and electronics, I just didn't count on the exhaust pipe being so long and being welded to the box. I got it even with the bottom of the floor joists when I realized if I tried angling it, it might get hung up causing a very dangerous situation trying to free it from underneath.

So why not pull it up the stairs you ask? It's a spiral staircase with 26" wide clearance and I'm too proud to ask for help from friends who are older and weaker than myself knowing they can't lift a 200# frame and I can't push it up the stairs either.

The solution: After field stripping the unit, place it on a handled dolly and strap her tight. Remove the cap from the center post on the spiral and install a come-along between the pipe and the dolly. Slowly crank it up and rebalance as you go since it will want to swing into and jamb up on the railings. When the come-along has wound up all it's line, hook the second come along ( you did remember to bring that upstairs with you right as the stove is now blocking the only exit path to the mechanics tools...) to a spot lower on the hand cart and place a strap around the stove and center spiral pipe, lift it up another foot. then hook something else to balance it while you remove Come-Along 1 and reposition it to a solid toggle screwed into a floor joist (don't the small tool hanger holding a woodworking hammer). Heave, haul add a lever or two as necessary to get the wheels onto the the top plate of the spiral then pull her into place.

Changing an ignitor or auger motor is nothing compared to simply placing the unit where it will be used...

Before I forget, and the final step before cleaning and re-assembly, replace the small tool hanger and put the word working hammer back...

:^)
 
Oh man I'd like to see pics of that HAH!
 
You must really want a pellet stove! Is the stove going in a loft or just the main level of a home (or an upstairs room)? If a loft or an upstairs room, I understand the one way up, but if on a main level (at least in my area) the building codes make you have more than one means of egress.
 
This is a second floor workshop in a garage. I custom built this 15 years ago instead of adding a pole barn. Initially designed so when it makes sense I can add an indoor staircase to connect the additional rooms and finish it off. Everything passed code when it was built because it was not living space. In the winter I've run a kerosene torpede heater (150K) on the first floor of the garage and pointed it towards the staircase. Heat rises and it warms up (slowly). That setup is expensive to operate and risky due to no venting for CO.

While looking for pellet grills this winter on CL, I saw a pellet stove and got the bug to install a safer heating method. I chose used to save a few bucks and first looked at an old St Croix Prescott (my first post). Decided against it and read up on the Harman burn system. Made sense so I waited till one became available at a reasonable price.

Picked up a decent hearth as well. At least this went up on the electric winch without issues.

Placement was a bi--h today, but I got it up (as described) without incident. It s all back to being assembled except for a couple of gaskets. The stove looks pretty simple after taking it apart.

I have a thimble with OAK on order as well as new gaskets for the exhaust pipe and burner weldment. Hopefully these arrive Saturday and I can finish up the install.

The next question is connecting Dura PeletVentPro pipes to the exhaust fitting. The PO gave me all his pipe and there was no appliance adapter. I think his installer used an adjustable pipe section in place of the adapter. Since I have the exhaust nipple off I looked at how it fits and it seems to make sense that this can be used this way but I'm not convinced. The nipple slides into the exhaust nipple and may seal with it's silicon gasket. However I can't guaranty the o-ring on the PVP is compressed. It would seem if you applied a little extra high temp silicon there would be no issues.

Is what I'm describing a legal use of an adjustable 3PVP-12/18 section? I can't find anyone recommending this using the search tool.

It may also be I've found the answer at: http://www.duravent.com/docs/product/pvp_harman_adapter_web.pdf

If not then it looks like I'm going to be delayed installing the thimble while I wait for an adapter and 12-18" normal pipe (locking devices on both ends.
 
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I have the ADHB adapter on order. I don't see any restrictions in the installation manual against fitting the adjustable pipe to this then sealing he joint with silicon tape. I also understand I can't use it for the adjustability feature. otherwise I'll have the same problem (venting inside the outer jacket) as I'm trying to avoid by adding the ADHB. This is about the only way I can see to make this serviceable (disassembling pipe) if a fan goes out in the future and the stove needs to be moved. Any comments?

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I had to change the vent design to achieve 12" to inner corner of a room. The only question left is should I direct vent horizontally or add a short vertical section inside for a little draft (~24"). It probably makes more sense to direct vent and consider a longer exterior vertical in the future if necessary. The required clearance to the window seems to be 12" when using outside air.

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The Harman adapter should make everything work nicely. I'm putting HPV silicon on the inside of my joints before putting them together, then wiping off the excess. I've seen it done that way on a few videos.
 
The Harman adapter should make everything work nicely. I'm putting HPV silicon on the inside of my joints before putting them together, then wiping off the excess. I've seen it done that way on a few videos.
Got the adapter in last night (USPS had delays this week) and started dry fitting everything. As many have said, the 3PVP-ADHB is a tight fit. I've been expanding the collar to make sure it covers a drilled hole used to secure the previous pipe to the flange. It will be the only joint sealed with high temp furnace cement when I'm ready for final assembly. The others will be silicone taped per recommendations above. The pipe to thimble interfaces (no joints) may also be sealed with this compound as I have a whole tube that will probably start drying out as soon as I cut the tip off.

I've looked at posts about servicing stoves and some (including above) imply the use of tape on internal joints allows for disassembly. Assuming the use of Pellet Vent Pro,, if you turn every joint till it is fully locked, I don't see a way to take it apart once the pipe is sealed at the thimble and connected to the flange of the stove.

I've eliminated the T, 90 and riser in the diagram so I have enough EVL margin later to add this outside the house for a larger rise. The 3PVP-06B pipe now connects directly to the pipe that passes through the wall (thimble). I've considered at the 06B pipe setting one end fully locked and the other unlocked before sealing the thimble. This would allow both ends to be half locked or one end unlocked. Doesn't seem legit, but the use of Silicone Tape would seal it,

I tried slipping an adjustable section over the 6" section to allow locking the 6" in place and securing the slip joint with screws, but it doesn't move freely like in the You-Tube videos and I had a devil of a time disassembling while new, so I can't see that working after several years. Also the use of an adjustable with tape doesn't make the above situation seem all that bad.

Of course, the best method may be lock everything into place and since it's a Harman, just unbolt the exhaust flange when servicing. Peace of mind for an extra $5.00 (new gasket) every time a motor goes out. The downside would be having to replace the gasket annually when cleaning the pipes. My vent will be over 10' off the ground and I don't care to balance on a ladder while trying to start a leaf blower. I have seen a video of making an adapter to blow the pipes out from inside the house with a shop vac after removing the combustion plate...

What do most people who service their own equipment finally decide on for disassembling the vent pipe?
 
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What do most people who service their own equipment finally decide on for disassembling the vent pipe?

Mine is not a direct vent, I have a 6 inch horizontal then a Tee with cleanout, then 6 feet of vertical, then a 90 and out through the wall (basement install). I take the cleanout cap off the bottom and run a 3" pellet stove brush that I bought at Lowe's up through the pipe till I hit the 90. Then I go outside and run the brush in until I hit the 90.
 
Mine is not a direct vent, I have a 6 inch horizontal then a Tee with cleanout, then 6 feet of vertical, then a 90 and out through the wall (basement install). I take the cleanout cap off the bottom and run a 3" pellet stove brush that I bought at Lowe's up through the pipe till I hit the 90. Then I go outside and run the brush in until I hit the 90.
The closer I get to cutting a hole in the side of the house the more bad assumptions I come across. Previously I bought Furnace Cement based upon recommendations at this site. However, it seems the search function may have taken me to a different forum such that the heat required to cure this may be at the limit of the stove and FC is predicted to crack easier than silicone from other posts. Went back to planning High Temp (600f) silicone and bought at Menards. I also tried to hook up the OAK hose to the P68 only to find that the flex hose from DuraVent is 2" and the connection at the stove is 3". Searched for a 3" ID to 2" OD adapter and only found sources in China and England. Had I know about the 3" fitting I would have considered buying the Harman thimble. While I could use two exhaust adapters to reduce from 3" to 2", I figured I might as well try to get the clean solution out of China. Also the flex hose in the Duravent kit isn't the best and I see it coming apart at a couple of spots as I started forming it. I don't think a minor air leak from the room into the flex pipe is a big deal.
 
Finished the install today, now I just need to paint the outside thimble plate to match the house. Siliconed the adapter to the exhaust outlet yesterday and added three screws for code then taped this morning. Screwed all pipes together tight (no no external screws) and taped joints.

The only thing left is to install the OAK hose on the stove when my adapter arrives. I'll post results of how well the SS Chinese reducer fits and any mods needed when it comes in. I think it's going to be a better solution than the Summit Racing parts. Also considering a 2:ID to 2"OD adapter for the OAK. It turns out the lip on the external thimbal plate is way too short when going through an exterior wall. The inclusion of a hose clamp for a 1/2" (?) nipple shows the manufacturer doesn't understand that houses are sheathed with OSB and exterior finishes (e.g., cement board, vinyl siding)... I'd highly recommend against purchasing the 3PVP-WTI

It's getting warm out so I can't tell how badly I oversized, but I doubt I'll have any concerns come next winter. This puppy puts out a lot of heat.
 
Thanks, I have it all apart right now and will be cleaning everything.

I bought the Harman thinking I could remove the hopper then remove a plywood subfloor panel and use an electric winch to pull it straight up to the second floor. Wrong! Even after field stripping it of all motors and electronics, I just didn't count on the exhaust pipe being so long and being welded to the box. I got it even with the bottom of the floor joists when I realized if I tried angling it, it might get hung up causing a very dangerous situation trying to free it from underneath.

So why not pull it up the stairs you ask? It's a spiral staircase with 26" wide clearance and I'm too proud to ask for help from friends who are older and weaker than myself knowing they can't lift a 200# frame and I can't push it up the stairs either.

The solution: After field stripping the unit, place it on a handled dolly and strap her tight. Remove the cap from the center post on the spiral and install a come-along between the pipe and the dolly. Slowly crank it up and rebalance as you go since it will want to swing into and jamb up on the railings. When the come-along has wound up all it's line, hook the second come along ( you did remember to bring that upstairs with you right as the stove is now blocking the only exit path to the mechanics tools...) to a spot lower on the hand cart and place a strap around the stove and center spiral pipe, lift it up another foot. then hook something else to balance it while you remove Come-Along 1 and reposition it to a solid toggle screwed into a floor joist (don't the small tool hanger holding a woodworking hammer). Heave, haul add a lever or two as necessary to get the wheels onto the the top plate of the spiral then pull her into place.

Changing an ignitor or auger motor is nothing compared to simply placing the unit where it will be used...

Before I forget, and the final step before cleaning and re-assembly, replace the small tool hanger and put the word working hammer back...

:^)

Damn! Very impressive....Remember, take a pic of the final install and post it here as we love our pics on this site.

I'm going to beat the rush and nominate you for our hall of fame. With an install such as yours, your nomination is a shoe in. Can I get a second?
 
The other lesson learned (an mentioned by others on the forum) is when buying a used pellet stove, don't put any value in the "expensive" piping that the PO is going to throw in.

The pipe that came with my stove was claimed to have cost $400 but upon inspection, it had been improperly installed with hidden damage. I might argue that it's possible to use an adjustable PVP pipe to connect to the exhaust flange on a Harman (with a bunch of sealant for the flange to inner-wall), but the right solution is an appliance adapter designed for the stove (Harman's are different than others). Improper installs can result in holes in the exhaust flange that may require replacing this component (or welding the holes shut, or flaring the adapter or...) and penetrations of the internal liner of double walled pipe (ask me how I know). Even if I tried to salvage the damaged pipe and 90 degree elbow, they weren't the correct components for my installation. The only safe and usable components from the PO were a single 3' pipe and the termination (which was installed outside). That said, I do have a tee, a 90 degree elbow and a piece of pipe that may be useful if and when I decide to add a vertical draft section outside the house, but for now, they sit in a corner and have no value...

If you get a 3PVP-HC2 in the deal and it's glued onto the end of a piece of pipe, think twice about removing it (as required) to thread the outside section of the thimble over the pipe. A little too much pressure on the end of the HC2 results in it breaking in half. It took the better part of two hours to make this usable again as the pipe appears to be shaped after the two sections are assembled (unfold a little of the pipe, try to assemble the joint, swear a bit, unfold some more, assemble the two sections using a prying motion then reform with a ball-peen hammer). Not fun.

I think I saved $50 -$70 in in what I could salvage from used pipe. New would have been easier and a lot less hassle. You're going to be buying pipe sections anyway, just order what you really need and know that the internal seals will be safe. What I finally realized is when it comes to venting, safety and proper installation is what matters (not saving $50).
 
Damn! Very impressive....Remember, take a pic of the final install and post it here as we love our pics on this site.

I'm going to beat the rush and nominate you for our hall of fame. With an install such as yours, your nomination is a shoe in. Can I get a second?

Here's a few shots.

20200405_114120[1].jpg

Hearth pad from Craigs list and exceeds all stated requirements. The Harman temp sensor runs horizontally across the back wall for now.
(Where do you put the harman cleaning tool, I haven't found a hanger in the stove yet. and on top of the hopper seems wrong..)

Fire extinguisher and ash bucket arriving next week.

I still need to install insulation and drywall on the back wall this summer. (and drywall above the stove) That's why I asked about pipe serviceability. Worst case it's a $6 outlet flange gasket.

The OAK hose (left) is attached to the thimble but not the stove. Waiting on a 3" to 2" adapter to arrive. For now it's just lettting air into the rear enclosure to ballance draft requirements.

20200405_114214[1].jpg

Hopefully this enables me to use these tools in the winter months. The workshop has been idled because of summer activities that take me away from home and once I have weekends available, it's just too cold. Same goes for finishing the drywall...

I think you'll be able to understand the challenges and the need to fields strip it down removing the hopper and motors before attempting to haul it up the stairs (single handed). The distance from the center post to the handrail was only a few inches wider than the stove itself...
20200405_114247[1].jpg

Remember, the cap on the center post comes off to allow the hook of the come-along to be safely supported.

20200405_114309[1].jpg

Sorry, no pictures of the stove hanging from the winch (and failing to make it through the floor joists) or pictures of the come-alongs hauling it up the Spitral. I 'll leave these to your imagination.

At least I was able to use the winch to haul the hearth pad up as the 48" width would have made the spiral stairs near impossible.

Next purchase will be an ash vac. While I have a fine dust filter in the little orange shop vac (under the window) , It doesn't have a blower output. From what I can tell, I'll need this due to the placement of the exhaust pipe outside. I don't think running a gas blower inside would be appreciated..

20200405_114547[1].jpg

The two pieces of pipe from the PO which I decided were usable and a new 3PVP-WTI thimble (PO included the inside plate from a 3PVP-WT. The outside plate had been taken apart to use only the metal ring to transition to/through a brick facade. Didn't make sense to me, but I wanted an OAK anyway...)

Clearance to ground: About 12'
Clearance to Window: 47" (only 12" required when using OAK)
Clearance to Soffit : Not measured but exceeds the NFPA requirements.
Clearance to house (without termination): ~18"

I know I need to trim the tree for my 3' combustible clearance.

One other comment, the exterior of the house is cement board (Hardy siding). When I built the garage I used a carbide circular saw blade for trimming this and there would be a big dust cloud. I didn't fancy cutting a hole using a circular saw and standing on an extension ladder so I tried a Bosch Carbide blade in a jigsaw which cut through this like butter from the inside of the house. Still enough dust to cloud my vision (the hole wasn't quite round), but not too bad and a lot safer.
 
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Nice install....And thanks for the pics. How many square feet are you heating with that beast?

One thing you might want to consider is installing a ceiling fan right where your receptacle is that the winch is plugged into. A hugger style with reversible blades.....You don't need anything fancy of course, just something to push the warm air back down from the ceiling and around the room.

Also, make sure you have the stove plugged into a quality surge protector. Not a cheap power strip.....Tripp Lite brand with a couple thousand joules protection minimum are pretty reasonably priced....

Here's the one I have my P61A plugged into:

 
SQFT? Only about 1000 max.. As I said, I know it's overkill, but the space may only be heated on weekends in the winter/spring when the outside (and inside )temp is below freezing. I wanted to make sure the room comes up to temp relatively fast and could have gone with a P43 or P61. However this one became available and posts on the forum said better to oversize than undersize. I think you can slow the feed rate down to reduce the output if necessary but based on forum posts I'm not sure if this will cause incorrect combustion (too low of a Fuel/AIr ratio?).

In general its a much better setup than the previous 150K BTU Kerosene torpedo heater on the first floor blowing heat (and CO) up the stairway to the second floor along with a 14K BTU vent free Kerosene heater (with CO detection) on the second floor to supplement since a lot of the 150K heat bounces back into the first floor of the garage.

I have a whole house surge protector so I was thinking of a small UPS to allow the stove to shut itself off gracefully. The only problem is the Harman recommended units are getting scarce and new UPS' have better sine wave approximations (even some cheaper ones). Not sure what the newest UPS is that the stove will recognize.

The fan is a good idea and I'll look into it this summer/fall. Right now the distribution blower is doing a fine job heating the room up from the mid 40's this morning. The pictures don't show the adjoining rooms and hallway, however they are currently only used for storage so the real focus is under 700SqFt. right now. If I ever finish this bonus area off as living space, I'll have a nice stove to keep me company in my mancave...

(As of this afternoon, the tree has been trimmed and there is more than a 3' clearance around the outlet of the pipe.)
 
The whole house surge protector is a good idea. Especially given you have all sorts of power tools.

And you're absolutely right about over sizing your stove....The P68 is pretty much exactly like the P61A and P43 in that it will idle down as needed depending upon what you have it set at and still burn relatively efficiently even when not calling for heat. It's better to have too much stove you can crank down than not enough stove when you need the heat output.

I run my stove in room temp./manual meaning it never shuts down when it reaches the heat setting. It just slows the feed rate automatically and the distribution fan stops.....Basically you're now only feeling the radiant heat from the stove itself.... As you probably already know, the room probe and EXP probe inside the exhaust area work in conjunction to regulate the heat output....
 
The whole house surge protector is a good idea. Especially given you have all sorts of power tools.

And you're absolutely right about over sizing your stove....The P68 is pretty much exactly like the P61A and P43 in that it will idle down as needed depending upon what you have it set at and still burn relatively efficiently even when not calling for heat. It's better to have too much stove you can crank down than not enough stove when you need the heat output.

I run my stove in room temp./manual meaning it never shuts down when it reaches the heat setting. It just slows the feed rate automatically and the distribution fan stops.....Basically you're now only feeling the radiant heat from the stove itself.... As you probably already know, the room probe and EXP probe inside the exhaust area work in conjunction to regulate the heat output....

According to the brochure, the P68 has a lower heating capacity than the P43 on the low end, and of course much much higher on the high end. Given that information, I'm not sure why anyone would buy a P43, except to save ~$1,000.

I run in room temp/manual when it's pretty cold outside, or when I'm trying to warm the house back up in the morning after turning it down over night. Then I either switch to room temp/auto, or turn it off completely.